I'm very glad to hear that LE have lots more information than they have shared so far.
When you say HF was being watched at the time do you mean actually overnight on the 30th? I've thought from the start that his alibi was some other kind of criminal activity but if he was literally being watched then I guess we can be pretty sure he wasn't directly involved.
If PP had doubts about EA I wonder if she would have invited him into her home at all.
JMO
If any of them had doubts about EA, you'd think they wouldn't allow Christina to walk alone with him especially when a ride was offered all the way to Ft. Worth. I'm not saying I think SN is necessarily involved but I don't think the fact they've been friends for so long is a reason to write him off. Look at all the parents who kill their kids. Victims of crime are often victimized by their supposed loved ones.